The Hist

This is it, the final Fighters Guild quest. Talk to Modryn Oreyn and he'll send you back down to Leyawiin to end the Blackwood Company once and for all.

Head to Leyawiin and enter the Blackwood Company quarters in the center of town. As you enter, three Blackwood Company members will attack you. Not one of them is particularly difficult, though fighting the three simultaneously can be a challenge. Try to lure them one-by-one into the side room to your right. If you can take down the fighter first you can then easily deal with the archers.

Loot the dead bodies to find the key to Jeetum Ze's room. Use the key to unlock the door on the second floor of the building. Inside, you should find Jeetum Ze (though we actually didn't see him until after we left the room, at which point he mysteriously appeared in the main hall of the building). Kill him, then loot his body for the key to Ri-Zakar's room. The key unlocks a door on the third level of the building, letting you in to kill Ri-Zakar and get the Blackwood Company Basement Key.

Go back to the ground floor of the building to find the basement door. Head inside and be ready to fight the two mages inside (they're pretty weak). With them killed, your next (and final) goal is to destroy the Hist tree. There are two loose pipes to find in the room. One is on a table to the south and the other is on the floor to the southwest. Pick 'em up, then activate the machinery on either side of the tree to destroy the Hist. As you leave the basement, Maglir will confront and attack you. Dispose of the pest.

Return to Modryn Oreyn and he'll tell you to inform Vilena Donton. Head to the Chorrol Fighters Guild and speak with Vilena, who will then promote you to Master of the Fighters Guild. Return to Modryn Oreyn and speak with him to complete the quest.

Now that you've completed the Fighters Guild quests, you can speak to Modryn Oreyn to oversee the general actions of the guild. You can tell him to have the guild focus on recruitment, which will earn the guild extra loot. Or if you tell Modryn to focus on contracts, the guild will focus on earning money. After every month, check the Guildmaster's chest on the top floor of the Chorrol Fighters Guild to collect the booty.